Field of the Invention
The present invention relates to a liquid crystal display apparatus, and more particularly, to a liquid crystal display apparatus that enables a collective drive lighting inspection.
Description of the Background Art
A technique for inspecting breaks in gate signal lines and source signal lines of semiconductor switching elements provided in a display region of a display panel and inspecting defects in pixels by lighting and non-lighting of the pixels in the display panel included in a liquid crystal display apparatus has been known. The inspection technique includes a technique, which has been known, for collectively inspecting a plurality of gate signal lines and a plurality of source signal lines by bringing an inspection needle into contact with an inspection terminal and for collectively controlling an input of an inspection signal to the gate signal lines and the source signal lines by a plurality of inspection semiconductor switching elements connected to the gate signal lines and the source signal lines.
Such collective inspection technique is different from an inspection technique for individually probing terminals of a plurality of gate signal lines and a plurality of source signal lines, and the collective inspection technique prevents an inspection device from influences of a resolution of the display panel and a design (such as the number of bumps) of a semiconductor chip, so that a general-purpose inspection at low cost can be achieved.
For the above-mentioned inspection technique, a lighting inspection circuit including the plurality of inspection semiconductor switching elements has been provided in a semiconductor chip mounting region in which a semiconductor chip is mounted. However, the semiconductor chip mounting region needs to be reduced in size due to a miniaturized semiconductor chip and a narrow frame of the display panel, so that the lighting inspection circuit is divided into a plurality of portions that are often provided in a region except for the semiconductor chip mounting region.
Upsizing and high resolution of a display panel in recent times causes distribution of a wiring resistance in a display plane, resulting in occurrence of display unevenness during the inspection by the collective control. To solve the concern of the display unevenness caused by the distribution of the wiring resistance in the display plane due to the upsizing and the high resolution of the display panel, Japanese Patent Application Laid-Open No. 2000-187451 has proposed a technique for adjusting lengths of wires to be equal in a lead-out region including the wires with different lengths to individually adjust the wiring resistance. The technique is applied to the plurality of wires that electrically connect a display portion to a semiconductor chip portion, and thus effects can be obtained in a drive (normal drive) method during manufacturing, and the display unevenness caused by the distribution of the wiring resistance can be prevented.
However, when wires in a collective drive inspection circuit are different from the plurality of wires to which the above-mentioned technique is applied, the display unevenness caused by the distribution of the wiring resistance may occur during the collective drive even in the display panel in which the display unevenness is prevented during the normal drive. The difference between the groups of the wires here is that the plurality of wires are completely independent of each other and have different resistances between the wires while the wires in the collective drive inspection circuit are a plurality of wires branching off from one common wire and the plurality of branched wires have approximately the same resistance. In other words, the common wire portion causes the distribution of the wiring resistance in the collective drive inspection circuit, so that the display unevenness fails to be improved by individually adjusting the wires as proposed in Japanese Patent Application Laid-Open No. 2000-187451.